Low force insertion connector

ABSTRACT

An electrical connector for use in conjunction with a printed circuit board having terminals on the surface thereof. The connector exerts minimal force on the circuit board terminals during insertion of the board into the connector and thereafter develops the contact forces required to maintain electrical continuity. The connector has a housing having a recess adopted to receive the terminal carrying portion of the circuit board. The recess is defined, in part, by a back wall and a bottom abutment and is of a size and shape such as to freely receive the board with the edge of the board engaging the abutment. A series of contacts are situated in the recess adjacent the wall in opposing relationship to the board terminals. The recess is so shaped relative to the board that the board may be received in the recess in an insertion position in which it is on the opposite side of the contacts from the back wall and relatively remote from the contact, and may be moved to a final position in which it is relatively close to the contacts and the back wall. The contacts are adopted to operatively engage the terminals as the board is moved to the final position but to make, at most, only minimal engagement with the terminals when the board is in the insertion position. Securing means on the housing are adopted to engage the board when the board is moved to the final position, and to retain the board in the final position.

I United States Patent [191 Pittman et a1.

[ 5] Nov. 18, 1975 LOW FORCE INSERTION CONNECTOR [75] Inventors: RobertD. Pittman, River Edge,

N.J.; Michael Offerman, Long Beach, NY.

[73] Assignee: Industrial Electronic Hardware Corporation, New York, NY.

[22 Filed: Dec. 4, 1974 21 Appl. No.: 529,332

Related US. Application Data [63] Continuation of Ser. No. 390,090, Aug.23, 1973,

abandoned.

[52] US. Cl. 339/91 R; 339/176 MP [51] Int. Cl. H01R 13/54 [58] Field ofSearch 339/75, 74, 91, 176

[56] References Cited UNITED STATES PATENTS [5 7] ABSTRACT An electricalconnector for use in conjunction with a printed circuit board havingterminals on the surface thereof. The connector exerts minimal force onthe circuit board terminals during insertion of the board into theconnector and thereafter develops the contact forces required tomaintain electrical continuity. The connector has a housing having arecess adopted to receive the terminal carrying portion of the circuitboard. The recess is defined, in part, by a back wall and a bottomabutment and is of a size and shape such as to freely receive the boardwith the edge of the board engaging the abutment. A series of contactsare situated in the recess adjacent the wall in opposing relationship tothe board terminals. The recess is so shaped relative to the board thatthe board may be received in the recess in an insertion position inwhich it is on the opposite side of the contacts from the back wall andrelatively remote from the contact, and may be moved to a final positionin which it is relatively close to the contacts and the back wall. Thecontacts are adopted to operatively engage the terminals as the board ismoved to the final position but to make, at most, only minimalengagement with the terminals when the board is in the insertionposition. Securing means on the housing are adopted to engage the boardwhen the board is moved to the final position, and to retain the boardin the final position.

Sheet 1 of 2 U.S. Patent Nov. 18, 1975 U.S.-Patent Nov. 18, 1975 Sheet 20f2 LOW FORCE INSERTION CONNECTOR This is a continuation of applicationSer. No. 390,090 filed Aug. 23, 1973 now abandoned.

This invention relates to electrical connectors and more particularly toan electrical connector for use with a printed circuit board whichexerts minimal force on the circuit board terminals during insertion butthereafter develops the normal contact forces required to insure goodelectrical continuity.

Printed circuit boards are extensively used throughout the electronicsindustry. For convenience, printed circuit boards are usually made toplug in and out of the chassis of the electrical component to which theyare attached, instead of being directly wired to the chassis. In thisway, they can be removed for easy repair or replacement, or to changethe operating characteristics of the device.

Generally, the printed circuit board is manufactured with a plurality ofterminals on a surface thereof. A connector is utilized to connect theprinted circuit board to the chassis. Normally, the connector is mountedon the chassis and has a series of wire connectors extending therefrom,each of which is wired to the appropriate portion of the chassis. Theprinted circuit board is plugged into the connector with each of itsterminals making electrical contact with the corresponding contact ofthe connector to connect the board to the circuit of the chassis.

It is a requirement of such connectors that each of the contacts of theconnector exert a prescribed amount of force on the printed circuitboard terminal associated therewith such that electrical continuity isinsured. This is generally accomplished by making the connector contactsof a resilient material which can be deflected as the circuit board isinserted into the connector, thus exerting the necessary force on theprinted circuit board terminals. However, it has been found that if thiscontact force is exerted during the insertion of the board, the boardterminals are scraped by the contacts as the board is inserted. Sincethe board terminals are generally made of a very thin coating ofconductive material on the circuit board, after many insertions theterminal may have been scraped or marred to the point where appropriateelectrical continuity can no longer be achieved between the terminal andthe contact.

Previous attempts to overcome this problem have proven unsuccessfulbecause these connectors require, after insertion, some device ormethod, apart from the connector housing itself, to develop the requiredforce between the contacts and the terminals which are necessary forgood electrical continuity. This, of course, is undesirable, because itadds to the complexity and cost of the device as well as the timenecessary to complete the insertion.

It is, therefore, the prime object of the present invention to providean electrical connector for use with a printed circuit board whichexerts minimal force on the board terminals during insertion of theboard into the l connector.

It is another object of the present invention to provide an electricalconnector for use with a printed circuit board wherein the normal forcesbetween the connector contacts and the board terminals necessary forgood electrical continuity are developed subsequent to board insertionwithout the use of devices or methods apart from the connector itself.

It is a further object of the present invention to provide an electricalconnector for use with printed circuit boards which can be releasablymounted to a chassis or another printed circuit board, as desired.

It is still a further object of the present invention to provide anelectrical connector for use with printedcircuit boards which is made ofreliable and sturdy parts takes up a minimal amount of space, and can beinexpensively manufactured.

In accordance with the present invention the connector comprises ahousing having a recess adopted to receive the terminal carrying portionof the printed circuit board. The recess is defined in part by a backwall and a bottom abutment and is of a size and shape to enable it tofreely receive the circuit board with the edge of the board engaging theabutment. A series of resilient contacts are situated in the recessadjacent the back wall. The recess is so shaped relative to the circuitboard that the board may be received therein in an insertion position inwhich it is on the opposite side of the contacts from the back wall andrelatively remote from the contacts, the board then being movable, as bypivoting, to a final position in which it opcratively firmly engages thecontacts.

In the insertion position the contacts make, at most, only minimalengagement with terminals and therefore no scratching or marring of thecontacts takes place. Once inserted, the board is pivoted about theabutment such that the terminals move toward the resilient contacts. Themovement of the board deflects the contacts, thus developing the forcesrequired for good electrical continuity. When the pivotal movement iscomplete, securing means provided on the housing engage the board toretain it in the final position.

Scraping of the terminals is prevented because the terminals are remotefrom the contacts during insertion. The forces on the contacts are notdeveloped until after insertion, when movement to the final positiontakes place. However, during this movement no scraping of the terminalsoccurs as the forces used to deflect the contacts act substantiallynormal to the terminal surface.

To the accomplishment of the above, and to other aspects as theyhereinafter appear, the present invention relates to an electricalconnector for use with printed circuit boards, as defined in theappended claims and as described in the specification, taken togetherwith the accompanying drawings, wherein like numerals refer to likeparts and in which:

FIG. 1 is an isometric view of the connector as a printed circuit boardis inserted therein;

FIG. 2 is a side cross-sectional view showing the printed circuit boardin the insertion position;

FIG. 3 is a view similar to FIG. 2 showing the printed circuit board inthe final position; and

FIG. 4 is a top cutaway view of the connector showing the securing meansas the circuit board is moved to the final position.

The electrical connector of the present invention comprises a housing,generally designated A, into which a printed circuit board, generallydesignated B, is inserted. Printed circuit board B is of the type whichhas a plurality of terminals C on the surface thereof. Housing A has arecess D adopted to receive the terminal carrying portion of circuitboard B. Recess D is defined, in part, by a back wall, generallydesignated E,

and a bottom abutment, generally designated F and is of a size and shapesuch as to freely receive board B with the edge of board B engagingabutment F.

A plurality of connector contacts, generally designated G, are situatedin recess D adjacent back wall E. Recess D is shaped relative to board Bsuch that board B may be received in recess D in an insertion positionin which it is on the opposite side of the contacts G from back wall Cand relatively remote from the contacts G, and may be moved, as bypivoting, to a final position in which it is relatively close tocontacts G and back wall E.

Contacts G make, at most, only minimal engagement with terminals C onboard B when the board is in the insertion position. However, thosecontacts G are adopted to operatively engage terminals C when the boardB has been moved to the final position. This permits the insertion ofthe board without exertion of forces on the terminals. The forcerequired to provide electrical continuity between terminals C and thecorresponding contacts G is developed as board B is moved to the finalposition. Securing means, generally designated H, are provided onhousing A to engage board B when the board is moved to the finalposition.

Means H will retain the board in the final position until i the board isto be removed from the connector.

The connector of the present invention can be used in conjunction with achassis or another printed circuit board. In order to mount theconnector on the chassis or the printed circuit board, means, generallydesignated I, are provided for removably securing the connector to thechassis or the circuit board. Further, each of the contacts G isprovided with a wire connecting member, generally designated J, whichextends out the bottom of the housing. After the connector has beenmounted, these members J will be wired or otherwise electricallyconnected into the circuit of the chassis or the printed circuit boardto provide an electrical connection between the chassis and the printedcircuit board B.

Referring now to FIG. 1, housing A is preferably produced of insulatingmaterial molded to form a single unit. A recess D adopted to accept theedge of the printed circuit board B is present along the length ofhousing A. The portion of board B whichis inserted into recess D hasterminals C situated thereon.

As can best be seen in FIGS. 2 and 3,recess D is defined by back wall Eand a multilevel bottom portion consisting of bottomabutment F and level10.The top of recess D is opened and the front is bound by a front wall12 which is considerably shorter than back wall E to permit entry ofboard B into the recess at an angle with respect to back wall E. Whenboard B is inserted into recess D, one corner of the leading edgethereof will rest on abutment F. Each terminal C will be opposite thecorresponding contact G which is situated adjacent back wall E but willbe relatively remote from opposing contact G.

Abutment F is a platform which forms a portion of the bottom of recessD. It acts as a fulcrum means about which the leading edge of board Bpivots as it is moved from the insertion to the final positions. In theinitial position board B makes an acute angle with the surface ofabutment F. Board B is then pivoted about abutment F until it issubstantially perpendicular to the surface thereof.

Back wall E is provided with a plurality of projections 14 which extend,within recess D, vertically from level 4 10 along the height of the wallE. Each pair of adjacent projections 14 forms a cavity in which one ofthe.

contacts G is situated.

Each contact G, because of the resilient characteristics of the materialfrom which it is made, is movable between an extended position (FIG. 2)in which it protrudes beyond the surface of the projections 14 and adeflected position in which it is wholly within the cavity. The movementof contacts G is caused by the pivot ing of board B about abutment Fwhich acts as a fulcrum towards the final position (FIG. 3). Theprotrusion of contact G beyond the cavity in the extended position islimited by the interior corner of abutment F,

which is adjacent the bottom section of contact G and acts as a barrierto prevent contact G from extending too far beyond the surfaceprojection 14 and thus interfering with the insertion of board B intorecess D. In the final position the leading edge of board B will be flaton.

abutment Fand the terminal side of board B willrest against the surfacesof projection 14 which act as a structural abutment to insure properpositioning of the board. In the final position each contact G iscompletely insulated from the remaining contacts by projections 14 whichprevent any electrical shorting be tween adjacent contacts G.

As board B is pivoted about abutment F towards the final position, theterminals C thereon will approach the protruding portion of thecorresponding contact G to deflect the contact. The deflection of thecontact will develop the force necessary to insure proper electricalcontinuity between terminals C and the respec tive contacts G. However,this is accomplished with minimal scraping or marring of the terminalsurface because the forces developed are substantially normal to theterminal surface throughout the movement of board B from the insertionto the final position, and, there is substantially no relativelongitudinal movement of the parts. When board B is in the finalposition it is substantially parallel to wall E and resting against thesurfaces of projections 14. The bottom edge of board B rests on abutmentF.

Securing means H are provided to retain board B in this position untilthe board is removed from housing A. Each securing means H consists of aleaf 16, made of resilient material, and a snap head 18 both of whichare situated on a projection 14. Preferably, leaf 16 and head 18 areintegral with the projection 14 to which they are mounted. Although onlytwo securing means H are shown in the drawings, it is obvious that asmany as necessary may be utilized depending upon the size of theconnector. For each securing means H utilized, a

slot 20 is situated along the board ,B in alignment with I thecorresponding leaf 16. Slots 20 run from the leading edge of board B alength at least equal to the height l of back wall E such that in thefinal position leaf 16 may be inserted therein to provide extrapositional sta-.

bility.

As seen in FIG. 4, snap head 18 is provided with an inclined surfacesuch that the head 18 is cammed aside by the edge of slot 20 such thatit passes through slot 20 As can be seen in FIGS. 2 and 3, each head 18has a lower beveled surface 22which permits board B to be.

inserted into recess D. Preferably, the inner comer of the front wall 12is also beveled for the same reason. These beveled surfaces facilitateinsertion of board B at the proper angle with respect to back wall E.

Extending from the bottom of each contact G through passages provided inlevel is a connector J which permits electrical connection of thecontact G to the circuit of the chassis to which housing A is mounted.This connection may be accomplished by wrapping wires about connector Jor otherwise, as desired.

In order to mount housing A to a chassis or another circuit board,removable securing means I are provided extending downward from eachside of housing A. Each means I comprises a snap head 24 which fits intothe appropriate opening in the chassis or circuit board to which housingA is mounted. The operation of snap head 24 is substantially the same asthat described for snap head 16. Preferably, snap heads 24 are offsetfrom each other, i.e. one placed near the front wall 12 and one towardsback wall E so that several connectors can be used side by side withoutinterference by heads 24, or to provide a polarizing control inconjunction with the panel on which they are mounted.

In operation, housing A is secured to a chassis by snap heads 24 andwired to the circuit by means of connectors J. The circuit board isinserted at an angle with respect to back wall E until the corner of theleading edge rests on abutment F. At this point terminals C are alignedwith but remote from corresponding contacts G. The board B is thenpivoted to the final position parallel to wall E thus deflecting thecontacts, and thus developing the necessary contact forces betweenterminals C and contacts G. In this position board B rests against thesurfaces of projections 14. During pivoting snap heads 18 pass throughslots 20 and secure the board in the final position. In this mode ofoperation, it can be seen that there is little or no contact between theterminals on board B and contacts G as board B is inserted in theconnector. While the board is pivoted from the insertion position to thefinal position, force is developed between the terminal C and contact Gbut it is normal to the surface of the terminal and therefore does notscratch or wear away the terminal. In this way, minimal force is exertedwhich can mar or scrape the terminal during insertion, and yet when theboard is moved to the final position the necessary forces are developedbetween the terminal and the contact to insure electrical continuity.

It has been assumed during the explanation that the electrical connectoritself has been fixed and the circuit board movable. However, ininstances when the reverse situation occurs, i.e. that the circuit boardis fixed and the connector is moved, the same mode of opera tion asdescribed can be used equally successfully. Further, certainapplications require fixed circuit boards and fixed connectors in adrawer-type relationship. The connector of the present invention canalso be used in this situation, even though its non-scrapingcharacteristic will not be utilized. In such a case instead of beinginserted in the insertion position and then pivoted to the finalposition, the board slides directly into the final position by aligningslots 20 with leafs l6 and then relatively moving the board and theconnector in parallel planes until the leading edge of board B rests onabutment F. Bevel 26 on the top of head 18 is utilized in this situationto facilitate entrance of board B directly into the final position. Somescraping force will be exerted 6 by contacts G on the terminals C duringthis insertion. However, due to the shape of the outer surface ofterminals G, which is inclined, the marring or scratching which occursin this type of insertion is minimized.

A single preferred embodiment of the present invention has beenspecifically disclosed herein for purposes of illustration. It isapparent that many variations and modifications may be made upon thespecific structure disclosed herein. It is intended to cover all ofthese variations and modifications which fall within the scope of thisinvention as defined by the appended claims.

We claim:

1. A low force insertion connector for use with a circuit board having aterminal on a surface thereof, said connector having a contact mountedthereon and being of the type in which the board is inserted into saidconnector in a first position wherein there is at most minimalengagement between said terminal and said contact and is movable to asecond position wherein operative engagement between said terminal andsaid contact is achieved, said connector comprising a housing having arecess therein, said recess being defined, in part, by a back wall, abottom wall, and a front wall, said contact being situated in saidrecess adjacent said back wall, and an'abutment within said recess andintegral with said bottom wall against which the bottom edge of saidboard is received, said abutment and another portion of said housingspaced forwardly of said contact defining a point facing said contactengaged by the corner of said board formed by the leading edge thereofand the surface thereof opposite the terminal carrying surface and aboutwhich said board pivots substantially on said corner as said board movesfrom the first position to the second position.

2. The connector according to claim 1 wherein said contact is movablebetween an extended position wherein it is relatively remote from theboard and a deflected position wherein it engages said terminal by themovement of said board to said second position.

3. The connector according to claim 2 further comprising means forguiding the board into said first position.

4. The connector according to claim 1 wherein said recess is opened atthe top and at least part of the front to permit the board to be pivotedabout said abutment between said first and second positions.

5. The connector according to claim 4 wherein said contact engages saidabutment so as to retain said contact in the extended position.

6. The connector according to claim 4 wherein said securing means isadapted to make a snap engagement with the board.

7. The connector according to claim 1 further comprising a securingmeans adapted to make a snap engagement with the board.

8. The connector according to claim 7 wherein said snap engagement isprovided by a member projecting from said back wall.

9. The connector according to claim 8 wherein said member comprises aflexible leaf portion integral with said wall and a snap head, said headbeing mounted on said leaf.

10. The connector according to claim 9 wherein said head has a beveledportion for guiding the board into said first position.

11. The connector according to claim 1 further comprising a circuitboard having a slot therein, and a securing means engaging the edge ofsaid slot to retain 7 said board in said second position.

12. The connector according to claim 11 wherein said securing meansmakes a snap engagement with said slot edge.

13. The connector according to claim 11 wherein said securing means ininsertable into said slot.

14. The connector according to claim 1 wherein the surface of said otherportion of said housing adjacent said pivot point is inclined to permitinsertion of said board such that said board corner is in proximity tosaid pivot point.

15. The connector according to claim 14 further comprising a securingmeans adapted to make a snap engagement with the board.

16. A low force insertion connector for use with a circuit board havinga terminal on the surface thereof, said connector having a contactmounted thereon and being of the type in which the board is insertedinto said connector in a first position wherein there is at most contactis achieved, said connector comprising a hous ing having a recesstherein, said recess being defined, in] l 3 part, by a back wall, abottom wall, and a front wall,

said contact being situtated in said recess adjacent said back wall, andan abutment within said recess integral with said bottom wall, saidabutment and another portion of said housing joining to form a pointabout which said board pivots as said board moves from the first to ythe second position, said pivot point being spaced from said contactalong said abutment so as to form an unobstructed opening between saidpivot point and said contact into which the board may be inserted, thepivot point engaging the board on the opposite side thereo from thecontact-engaging side thereof.

- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO.3,920,303

DATED 1 November 18, 1.975

INVENTOR(S) ROBERT B. PIT'I'MAN and MICHAEL OFFERYAN It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Please change inventof's name from ROBERT E. PITTMAN to ROBERT B.PITTMANO Signed and Sealed this seventeenth D ay Of February 1976 [SEAL]Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ofPatenrsand Trademarks

1. A low force insertion connector for use with a circuit board having aterminal on a surface thereof, said connector having a contact mountedthereon and being of the type in which the board is inserted into saidconnector in a first position wherein there is at most minimalengagement between said terminal and said contact and is movable to asecond position wherein operative engagement between said terminal andsaid contact is achieved, said connector comprising a housing having arecess therein, said recess being defined, in part, by a back wall, abottom wall, and a front wall, said contact being situated in saidrecess adjacent said back wall, and an abutment within said recess andintegral with said bottom wall against which the bottom edge of saidboard is received, said abutment and another portion of said housingspaced forwardly of said contact defining a point facing said contactengaged by the corner of said board formed by the leading edge thereofand the surface thereof opposite the terminal carrying surface and aboutwhich said board pivots substantially on said corner as said board movesfrom the first position to the second position.
 2. The connectoraccording to claim 1 wherein said contact is movable between an extendedposition wherein it is relatively remote from the board and a deflectedposition wherein it engages said terminal by the movement of said boardto said second position.
 3. The connector according to claim 2 furthercomprising means for guiding the board into said first position.
 4. Theconnector according to claim 1 wherein said recess is opened at the topand at least part of the front to permit the board to be pivoted aboutsaid abutment between said first and second positions.
 5. The connectoraccording to claim 4 wherein said contact engages said abutment so as toretain said contact in the extended position.
 6. The connector accordingto claim 4 wherein said securing means is adapted to make a snapengagement with the board.
 7. The connector according to claim 1 furthercomprising a securing means adapted to make a snap engagement with theboard.
 8. The connector according to claim 7 wherein said snapengagement is provided by a member projecting from said back wall. 9.The connector according to claim 8 wherein said member comprises aflexible leaf portion integral with said wall and a snap head, said headbeing mounted on said leaf.
 10. The connector according to claim 9wherein said head has a beveled portion for guiding the board into saidfirst position.
 11. The connector according to claim 1 furthercomprising a circuit board having a slot therein, and a securing meansengaging the edge of said slot to retain said board in said secondposition.
 12. The connector according to claim 11 wherein said securingmeans makes a snap engagement with said slot edge.
 13. The connectoraccording to claim 11 wherein said securing means in insertable intosaid slot.
 14. The connector according to claim 1 wherein the surface ofsaid other portion of said housing adjacent said pivot point is inclinedto permit insertion of said board such that said board corner is inproximity to said pivot point.
 15. The connector according to claim 14further comprising a securing means adapted to make a snap engagementwith the board.
 16. A low force insertion connector for use with acircuit board having a terminal on the surface thereof, said connectorhaving a contact mounted thereon and being of the type in which theboard is inserted into Said connector in a first position wherein thereis at most minimal engagement between said terminal and said contact andis movable to a second position wherein operative engagement betweensaid terminal and said contact is achieved, said connector comprising ahousing having a recess therein, said recess being defined, in part, bya back wall, a bottom wall, and a front wall, said contact beingsitutated in said recess adjacent said back wall, and an abutment withinsaid recess integral with said bottom wall, said abutment and anotherportion of said housing joining to form a point about which said boardpivots as said board moves from the first to the second position, saidpivot point being spaced from said contact along said abutment so as toform an unobstructed opening between said pivot point and said contactinto which the board may be inserted, the pivot point engaging the boardon the opposite side thereof from the contact-engaging side thereof.